Dressing Your Baby for the Night: How to Get It Right
Which clothing fits which bedroom temperature? We explain TOG values for sleep sacks and share tips for restful baby sleep.
Written by Wetterbaby Editorial Team on April 3, 2025
Dressing a baby at night leaves many parents in the dark in the first months, literally and otherwise. Too warm, too cool, just right? The worry is justified, because the wrong combination disturbs sleep.
The reason is physiology. Babies can't regulate their body temperature as reliably as adults. What feels pleasantly cool to you can already be too much or too little for a newborn. What counts is the room temperature, not your own sense of comfort.
And it can sit lower than many people assume: 16 to 18 °C (61 to 64 °F) is considered ideal. That sounds brisk, but there's a good reason for it. Overheating is a bigger risk during sleep than slightly cooler air.
What Should Your Baby Wear at Night?
The basic setup stays the same at every temperature: a bodysuit (onesie), pajamas, and a sleep sack (called a sleeping bag in the UK and Australia) on top. It can't slip over the face, which makes it a better choice than a blanket, as the recommendations for a safe sleep environment set out. What changes is the thickness, graded from warm to cool:
- 25 to 27 °C (77 to 81 °F): a short-sleeve bodysuit with a thin 0.5 or 1.0 TOG sleep sack
- 23 to 24 °C (73 to 75 °F): a short-sleeve bodysuit and thin pajamas in a 0.5 TOG sleep sack, or the pajamas alone if the sleep sack is 1.0 to 1.5 TOG
- 21 to 22 °C (70 to 72 °F): a long-sleeve bodysuit and pajamas, sleep sack with 0.5 to 1.5 TOG
- 18 to 20 °C (64 to 68 °F): a long-sleeve bodysuit, pajamas, and thin socks, sleep sack with 1.5 to 2.0 TOG
- 16 to 17 °C (61 to 63 °F): a long-sleeve bodysuit, pajamas, and thin socks, sleep sack with 2.0 to 2.5 TOG
These are guide values. Which TOG value suits which room temperature is something we break down separately. Sleep sacks sold in the US often carry no TOG rating; as a rough guide, a light muslin or cotton sleep sack is about 0.5 TOG and a warm quilted winter one 2.5 TOG. Every baby runs a little warmer or cooler: some consistently need a touch more, others less.
A hat, by contrast, doesn't belong in bed at any temperature: babies regulate their warmth through the head, and a hat during sleep can quickly lead to overheating.
Why Layers Beat One Thick Piece
Several thin layers have a practical advantage: you can remove one at night without changing your baby completely. What matters is that the material breathes. If moisture builds up, your baby sweats despite thin clothing. Synthetics directly on the skin are a poor choice for that reason; cotton or wool-silk is better.
Checking Your Baby's Neck
The most reliable check costs nothing: place two fingers on the back of your baby's neck. If it feels warm and dry, the clothing is right. If it's sweaty, take a layer away. Cold hands or feet, by contrast, aren't a reliable signal, since circulation in the extremities isn't fully developed yet in babies.
If the judgment call is hard in everyday life, the Wetterbaby app helps: based on the weather and the room temperature, it gives concrete clothing recommendations for day and night.
Source:
kindergesundheit-info.de, The right sleep environment for your baby (in German)
